I suggest that you...

Regular Expression

I know that GG supports wildcards (*) in the lists which will help when you're trying to block something like 123Movies who keep changing their TLD (123movies.to, 123movies.co, etc.hahahaha) but, this doesn't seem to help when you need to block something more complex.

For example, we currently added https://sites.google.com/site/subgfyfs/jgghj where a student is using Google Sites to host games and claims it can NEVER be (hahaha). Anyway, I want to be able to design something that will block Flash content on Google Sites.

Using something like sites.google.com/site/*.swf may do the trick, but no documentation seems to indicate that the wildcard can be used in the middle of the text. If it does, then fine.

What would be great though, is the option to use Regular Expressions to locate matching strings. An example would be: